From f16009527595ee562308653bc3d0039166d2ab15 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Thu, 19 Mar 2009 20:26:16 +0100
Subject: [PATCH] perf_counter: fix up counter free paths
Impact: fix crash during perfcounters use
I found another counter free path, create a free_counter() call to
accomodate generic tear-down.
Fixes an RCU bug.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Orig-LKML-Reference: <20090319194233.652078652@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/perf_counter.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 99d5930f0a525..97f891ffeb406 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -1150,6 +1150,11 @@ static void free_counter_rcu(struct rcu_head *head)
kfree(counter);
}
+static void free_counter(struct perf_counter *counter)
+{
+ call_rcu(&counter->rcu_head, free_counter_rcu);
+}
+
/*
* Called when the last reference to the file is gone.
*/
@@ -1168,7 +1173,7 @@ static int perf_release(struct inode *inode, struct file *file)
mutex_unlock(&counter->mutex);
mutex_unlock(&ctx->mutex);
- call_rcu(&counter->rcu_head, free_counter_rcu);
+ free_counter(counter);
put_context(ctx);
return 0;
@@ -2128,10 +2133,10 @@ __perf_counter_exit_task(struct task_struct *child,
list_entry) {
if (sub->parent) {
sync_child_counter(sub, sub->parent);
- kfree(sub);
+ free_counter(sub);
}
}
- kfree(child_counter);
+ free_counter(child_counter);
}
}
--
GitLab